The invention relates to a method and an apparatus for the automatic provision and transfer of a reserve lap from a reserve position to a working position in a machine for processing wound laps and for the automatic discharge of empty tubes from the working position to the delivery position for example.
In order to avoid unnecessary standstill periods in machines which process wound laps, e.g. combing machines or ribbon lap machines, it is known to keep a reserve lap on stand-by in addition to the wound laps which are being processed. Such a device is present for example in the combing machine E715 (Rieter""s brochure xe2x80x9cKxc3xa4mmerei [Combing Plant]xe2x80x94Impressum 1403d-0991xe2x80x94Printed in Switzerlandxe2x80x9d). The empty tubes are transferred by hand to a collection position for a conveying system and thereafter the individual reserve laps are manually conveyed to the respective working position. This process requires a relatively high amount of time and can lead to damage to the outer web in the case of improper handling of the reserve lap.
A device is known from JP-63-27449, whereby a reserve lap is kept on stand-by behind the working lap on a downwardly inclined roll-off surface. In order to keep the reserve lap in this stand-by position, a swivelable plate is arranged in the zone of the roll-off surface which can be transferred via an adjusting mechanism from the locking position to the release position. A swivelable receiver for the empty tube which is ejected rearwardly by means of an ejection device is disposed below the roll-off surface. Said swivelable receiver is connected with the adjusting mechanism for unlocking the swivelable plate. This means that before the reserve lap is released for rolling down to the working position, the empty tube is transferred downwardly to the receiver via a pass-through opening between the roll-off surface and the working position. This device leads to the disadvantage that the reserve position is disposed relatively far at the back at a large distance from the working position. This is necessary in this embodiment, because the rearwardly ejected tube requires a certain amount of free space for delivery to the receiver. This device therefore requires much space, particularly as seen in the width, and also blocks the accessibility for maintenance work for the units which are situated in the bottom and rear areas of the combing machine. As a result of the relatively long roll-off path which the reserve lap needs to cover to the working position, damage or deformation can occur to the outer lap layer.
It was further proposed in EP-593 391 A1 to provide a swivelable bowl for the transfer of the reserve lap to the working position. This is also achieved with this device. This apparatus is provided with a swiveling device for the bowl in which the reserve lap is disposed. Furthermore, an additional receiver is provided for the rearwardly ejected empty tube. This device is temporally independent of the conveying system via which new reserve laps are supplied and empty tubes are discharged.
As a rule, however, the conveying system of the aforementioned embodiment is not charged to capacity and still has unused time reserves.
A centrally controlled lap conveying device is known from EP-381 960, with groups of laps and empty tubes being conveyed in a controlled manner by means of a crane bridge between combing machines and lap-forming machines. The method in which the empty tubes are supplied to the grippers on standby in the rails of the combing machines is not described.
From JP-OS-4-263620 a conveying system is known, with the conveying system being provided with two grippers. One of the grippers brings a reserve lap to the combing machine and is provided with a piecing apparatus for the lap end, while the second gripper removes the empty tube from the working position. This design is relatively complex and, in addition, no deposit for reserve laps is provided in the combing machine. As a result, this system is fully dependent on the availability of reserve laps from the conveying system.
A system of several combing machines with a lap-forming machine is known from JP-OS-52-25125, with the wound laps and the empty tubes being conveyed to a group by means of a conveying system (suspended conveyor) which is provided with grippers. A reserve position for receiving reserve laps is not shown. As a result, the individual combing machine can only be equipped with new wound laps once the empty tubes have been removed from their working position in the combing machine. Nothing is mentioned therein about any automatically controlled conveying system.
EP-A2 312 503 shows a conveying device for wound laps and empty tubes with an overhead conveyor with a craneway. A double gripper is provided which is used to take up the empty tube simultaneously when delivering a new wound lap to the machine. No reserve laps are shown in the machine and the empty tubes must be disposed in a special receiver, as otherwise the simultaneous exchange of the new wound lap is not possible.
EP-PS 118 600 shows a conveying device in which an additional receiver is provided on the lap carrier in order to creel the empty tubes manually for the return transport to the lap-forming machine. No automatic and effective change of the tubes can be performed with this device. A similar device is also shown in DE-OS 24 34 898 where the empty tubes are manually creeled for return transport on an additional holder on a movable gripper.
It is an object of the invention to provide a simple and cost-effective apparatus and method to follow-up reserve laps in lap-processing machines, with the smooth discharge of empty tubes being ensured and existing capacities of a conveying system being utilized optimally.
Briefly, the invention provides an apparatus and method for the automatic transfer of wound laps from a reserve position to a working position in a lap processing machine and an automatic removal of empty tubes from the machine.
In one embodiment, the apparatus comprises a lap forming machine for forming wound laps on tubes that include a control unit for operating the machine, a conveyor for receiving a plurality of wound laps from the lap forming machine and at least one combing machine having at least one working head for receiving a wound lap from the conveyor. The combing machine includes at least one transfer device for moving a wound lap from a reserve position to a working position in the working head and a control unit for operating the combing machine and for operating the transfer device;
In addition, the apparatus includes a conveying system for selectively conveying at least one wound lap from the conveyor to the combing machine and at least one empty tube from the combing machine to the conveyor. This conveying system also includes a control unit for operating system.
In accordance with the invention, a central control unit is operatively connected to each control unit for selective actuation thereof to effect movement of at least one wound lap from the lap forming machine to a reserve position in the working head, removal of an empty tube from a working position to the conveyor and movement of a wound lap from the reserve position to the working position.
The method for automatically transferring wound laps to a lap processing machine comprises the steps of actuating a conveying system to automatically place a reserve wound lap in a reserve position of the lap processing machine; thereafter monitoring the run-out of a wound lap in a working position of the lap processing machine and emitting a signal in response to the detection of an empty tube in the working position; actuating the conveying system to remove the empty tube from the working position in response to the signal; and actuating the conveying system to transfer the reserve wound lap from the reserve position to the working position.
The method further includes the step of actuating the conveying system to move a fresh wound lap into the reserve position to begin a new cycle.
In another embodiment, the conveying system is used to convey the empty tube from the working position to an intermediate position defined by the position of the reserve lap. In this embodiment, transfer of the reserve lap from the reserve position to the working position allows for an automatic transfer of the empty tube from the intermediate position into the reserve position. The conveying system is then actuated to remove the empty tube from the reserve position.
It is proposed that a conveying system is provided through which wound laps or empty tubes are conveyed individually or in groups between a lap-processing and a lap-forming machine. The empty tube is taken by the conveying system directly without any intermediate storage. This allows a compact design of the combing machine as seen in the width and leads to a favorable capacity utilization of the available conveying system.
The optimization of the conveying orders is enabled by the central control unit. The connection of the central control unit with the monitoring systems in the combing machines ensures that the combing machines can be serviced in a time-optimized manner via the conveying system on the basis of the indicated times of change.
Sensor means are preferably provided in order to monitor the pull-off of the lap roll (xe2x80x9cwound lapxe2x80x9d) disposed in the working position. This monitoring can be performed in different ways, e.g. by continual measurement of the length of the unwound web or by continuous measurement of the diameter of the wound lap.
The sensor means can also consist of a time function element which, via a roll-off mechanism produces a signal for the imminent change of lap and sends the same to the central control unit, so that the same can initiate the displacement of the conveying means depending on the entire system on time. In addition to such a sensor, a further sensor is usually provided which scans the tube surface (black/white) in order to signalize the actual pull-off of the tube. With this device, it is possible to send a signal on time to the control unit of the conveying system, so that the same is also ready during an imminent change of lap or empty tube in order to perform the change on time.
To ensure that the lap-processing machine is provided with reserve laps on time, sensor means are proposed which monitor the reserve position for the reserve laps.
The invention further provides an arrangement to facilitate the transfer of the wound lap and empty tube between the working and reserve positions of a working head of a combing machine. This arrangement includes a pair of lap rollers that define a working position for receiving a wound lap and for discharging a lap therefrom and that are rotatably mounted in a common horizontal plane as well as a receiver disposed below this plane to define a reserve position for receiving a wound reserve lap thereon. In addition, an inclined guide means extends from the working position downwardly towards the reserve position to guide an empty tube thereon towards and into the receiver and an ejection device is provided for transferring an empty tube from the working position onto the guide means.
This arrangement cooperates with the controlled conveying system for transferring a reserve lap from the reserve position into the working position and for removing an empty tube from the receiver.
As a result of this arrangement, the required space for attaching a receiver can be kept to a minimum. Only one common receiver is required for the reserve lap and the tube to be discharged. The proposed device further ensures that during the transfer of the reserve lap via the conveying system to the working position, there is an automatic and independent transfer of the tube from an intermediate position to the delivery position.
It is proposed further that an adjustable stop be provided in the zone of the guide means that can be moved into the roll-off path of the ejected empty tube in order to block movement of an empty tube towards the receiver. In addition, the stop is made to be responsive to a transfer of a reserve lap from the receiver to allow movement of the empty tube into the receiver. The stop prevents that the ejected tube from coming to rest on the circumference of the reserve lap as this could lead to damage to the outermost lap layer when the reserve lap is lifted for transfer to the working position. The proposed actuation of the stop is such that once the reserve lap has been lifted to a certain position, the blocking element is moved from the zone of the guide means and the tube is released for further transfer to the receiver.
Preferably, the guide means is in the form of a guide surface, such as a a ramp, on which the ejected tube can roll off to the receiver.
The apparatus is preferably provided on several working heads (e.g. combing heads in combing machines), as a result of which a simultaneous or groupwise change of laps can be performed in the machine.
The use of an overhead conveying system has proven advantageous as a conveying means for transferring the reserve laps and the discharge of the empty tubes. In this way, the surface space required can be kept to a minimum in the spinning room and the existing conveying capacities can be utilized optimally.